This project will examine how the visual system assigns colors to objects and locations in three different experimental paradigms. In the illusory conjunction paradigm, subjects sometimes perceive briefly presented colors and shapes in incorrect combinations. For example, a stimulus array containing a red X and blue H, when briefly presented (e.g. 100ms), will sometimes be perceived as containing a blue X. In the neon colors lines. The final paradigm involves the assignment of colors to objects in peripheral vision. A common theoretical framework can be applied to all three paradigms. The hypothesis is that the visual system integrates (combines) information over perceptual units. Perceptual units are defined in three broad ways. 1. Perceptual units are defined by the geometric properties of surfaces such that color information is integrated over adjacent areas or areas that are coherent in the Gestalt sense. 2. Units are affected by attention so that the assignment of color to objects can be cognitively penetrable. 3. With word and word-like stimuli made of colored letters, units are defined by the linguistic properties of letter string. In addition to looking at the effects of perceptual structure (units) in the three paradigms, it will be possible to directly compare the paradigms in terms of color psychophysics. Preliminary research indicates that the process of integrating information may be the same across the three paradigms. In understanding these phenomenon, both cognitive factors and basic visual processes will be considered.